The present invention relates to an X-ray CT (Computed Tomography) apparatus and, more particularly, to an X-ray CT apparatus for capturing an image of a subject in which a contrast agent is injected.
In an X-ray CT apparatus for capturing an image of a subject in which a contrast agent is injected, prior to a main scan, a helical scan is started synchronously with arrival of the contrast agent at a region of interest (ROI) in a monitoring scan executed with a dose lower than that of the main scan. In this case, after the scan starts, the helical scan with constant progress speed is performed (refer to, for example, Japanese Unexamined Patent Publication No. Hei09 (1997)-327454).